The present disclosure relates generally to the field of wireless identification systems. More specifically, the present disclosure relates to systems and methods for detecting when a wireless identification device, such as a Radio Frequency Identification (RFID) card or tag, has moved within the proximity of a wireless identification system.
RFID systems allow for convenient wireless identification and tracking of people and/or objects for various types of applications. For example, RFID systems may be used in access control applications, such as allowing users to access protected areas by holding an RFID card within proximity of a card reader coupled to a door lock. Other example applications of RFID systems include tracking products (e.g., in a retail environment), tracking people in a hospital environment, or enabling users to wirelessly process payments (e.g., using a wireless point-of-sale RFID detection system).
An RFID detection system can identify an RFID device (e.g., an RFID tag or card) when the detection system detects that the RFID device has entered the proximity of the detection system. One way to detect when an RFID device has come within proximity of the detection system is to continuously keep the detection system in an active polling mode. In the active polling mode, the detection system transmits polling signals that RFID devices within proximity of the detection system can receive. The RFID devices may then respond to the polling signals, indicating to the detection circuit that the devices are within proximity of the detection circuit and that an identification determination should be made by the detection circuit with respect to the devices.